Credentials include identification cards, driver's licenses, passports, and other documents. Such credentials are formed from credential or card substrates including paper substrates, plastic substrates, cards, and other materials. Such credentials generally include printed information, such as a photo, account numbers, identification numbers, and other personal information. Credentials can also include data that is encoded in a smartcard chip, a magnetic stripe, or a barcode, for example.
Credential production devices process credential substrates by performing at least one processing step in forming a final credential product. A card substrate laminating device performs a transfer or laminating process using a transfer ribbon. The transfer ribbon generally includes a continuous web liner or carrier layer to which a transfer layer is removably attached. The card substrate laminating device bonds the transfer layer to a surface of a card substrate using a heated roller.
The transfer layer may generally be one of two types: a patch laminate, or a fracturable thin film laminate. The patch laminate generally includes a pre-cut polyester film that has been coated with a thermal adhesive on one side. The pre-cut patch is attached to the liner with the thermal adhesive side exposed and available for lamination to the substrate. The heated roller is used to heat the patch to activate the adhesive, and press the patch to a surface of the card substrate to bond the patch onto the surface. The carrier layer is then removed from the bonded patch to complete the lamination process.
Fracturable thin film laminates are generally continuous resinous materials that have been coated onto the carrier layer. The side of the thin film laminate that is not attached to the carrier layer is generally coated with a thermal adhesive, which is used to create a bond between the thin film laminate and the surface of the card substrate. The heated roller of the laminating device is used to activate the adhesive and press the thin film laminate against the surface of the substrate to bond the thin film laminate to the surface. The removal of the carrier layer from the bonded thin film laminate completes the lamination process. The thin film laminate provides protection to the surface of the card.
The transfer layer may also operate as a print intermediate, on which an image may be printed in a reverse-image printing process. In the reverse-image printing process, an image is printed to the exposed side of the transfer layer (i.e., patch laminate or thin film laminate). Next, the image on the transfer layer is registered with the card substrate. The heated roller is used to activate the adhesive on the imaged transfer layer causing the imaged transfer layer to bond to the surface of the card substrate. The carrier layer of the transfer ribbon is removed from the bonded imaged transfer layer to complete the transfer of the image to the card substrate. The transfer layer provides protection to the image and the surface of the card substrate.
Heated rollers of conventional card substrate laminating devices have a relatively large circumference relative to the size of the surface of a card substrate, which is conventionally 3.375 inches long by 2.125 inches wide. For example, typical card laminating devices use a heated roller having a circumference of greater than approximately 2.0 inches. As a result, a conventional lamination operation may be performed by the heated roller on a card substrate, which is fed past the heated roller with the short edge leading, by rotating the heated roller less than two times.
Conventional card laminating devices have utilized such large heating rollers because those of ordinary skill in the art believed a high heat capacity roller (e.g., 21 J/° C. per inch of roller length) was necessary to perform satisfactory transfer lamination operations on card substrates, since such rollers would be capable of maintaining a near continuous transfer of heat to the transfer layer during the lamination operation, thereby ensuring uniform heating of the transfer layer. Additionally, the high heat capacity ensures that the temperature of the large heated roller would not change significantly during a transfer lamination operation. This allows the large heated roller to maintain a desired temperature during the performance of multiple lamination operations.
Downsides with the use of the large heated roller are evident during the initial startup of the device, and when it is necessary to process a single card substrate. For example, laminating devices using the large heated roller generally require a long warm-up time before the first card lamination operation can be performed due to the high heat capacity of the large heated roller. Thus, a user may experience significant delays before processing a single card substrate. Additionally, a large amount of energy must be used to initially heat the roller to an operating temperature at which it is capable of performing a card lamination operation, due to its high heat capacity. When only a single card is to be processed, the energy efficiency of the card lamination operation can be quite low.